Lets say when a stock and it's future is trading at aborice differential we can exploit the price differential by shorting the stock as the stock is trading at a premium and buying the future eventually when the price converges we can bag in the riskless profit
Example let's say the stock A is selling at 609 and it's future is selling at 590 so here we can short one lot of the stock and buy the future we bag in the riskless profit